1. Field of the Invention
The present invention generally relates to a packaging system and, more particularly, to an improvement in and over a product diverting mechanism used in the packaging system.
2. Description of the Prior Art
Prior to shipment of products manufactured at a factory to wholesale stores and retail stores, it is a customary practice to package predetermined numbers of the products in corrugated cardboard boxes. While this packaging operation is often carried out by hand, various packaging systems that automate the packaging operation have also been suggested.
Such automatic packaging system is generally of a design in which a plurality of products that are lined up are sucked upwardly by, for example, a vacuum suction unit and are then stacked one above the other. In such case, where the products are arranged in a single row, suction and stacking are performed a considerable number of times. Accordingly, in order to reduce the cycle time per box, it can be contemplated to arrange the products in a plurality of rows and the products in those rows are sucked all at a time and then to stack them one above the other.
On the other hand, if the cycle time of the packaging operation is reduced as described above, the necessity will arise to increase the speed at which the products are diverted so as to form a plurality of rows of the products.
In view of the foregoing, a primary object of the present invention is to provide a product diverting mechanism for diverting the products so as to line up in a plurality of rows, which can contribute to increase of the speed at which the packaging operation is performed in the packaging system.
While the assignee of the present invention has filed an application for patent in Japan on an invention of a mechanism capable of increasing the diverting speed, another important object of the present invention is to provide the product diverting mechanism of the type referred to above which can perform a diverting operation assuredly and reliably even though the products to be diverted have a varying height.
In order to achieve these objects, the present invention in accordance with one aspect thereof provides a product diverting mechanism for diverting products on a transport means in a packaging system for packaging the products that have been transported from a preceding processing station. This product diverting mechanism includes a force applicator for applying a force, containing a force component acting in a horizontal direction, to the products being transported, in a direction transverse to a direction of transport of the products, a suppressor disposed above the transport means for suppressing an upward shift of the products which occurs when the force applicator applies the force to the products, an elevator for moving the suppressor up and down, and an elevation controller for controlling the elevator to lower the suppressor to thereby allow the suppressor to be brought into contact with an upper surface of each of the products during diverting of the products.
According to the present invention, since the force containing the horizontally acting force component is applied in a direction transverse to the direction of transport of the products, it is possible to divert the products leftwards and rightwards to form two rows of the products with respect to the direction of transport. Also, by adjusting the extent to which the products are diverted, not only can the two rows of the products be formed, but it is also possible to divert the products into three or more rows. Since in the present invention the products are diverted by the utilization of a mechanism of applying the force to the products in a direction transverse to the direction of transport of the products, the handling speed during the diverting operation can be decreased as compared with the prior art mechanism in which the products are retained by the suction holder which, after the products so sucked have been transported, is subsequently released from vacuum.
However, if the force containing the horizontally acting force component is applied by the force applicator in the direction transverse to the direction of transport, and where the applied force contains a vertically acting force component, there is a possibility that the product applied with such force will xe2x80x9cfloatxe2x80x9d above the transport path, resulting in difficulty to accomplish the diverting operation. In particular, where the diverting speed at which the diverting of the product is executed is increased, the product will float above the transport path by the action of the force applied by the force applicator to the product with the horizontally acting force component no longer acting on the product sufficiently and, therefore, there is a high possibility that the position of the products after having been diverted will not be constant.
In view of the foregoing, in the present invention, the use has been made of the suppressor to suppress an upward shift, that is, floatation, of the product above a predetermined level above the transport path. The use of the force applicator in combination with the suppressor is effective to allow the products to be securely diverted to predetermined positions.
If the type of the products is varied and/or the products have a varying thickness (height) as a result of variations from product to product, adjustment of the level of the suppressor to compensate for a change may be necessary. However, according to the aspect of the present invention, the suppressor is lowered during the diverting operation to contact an upper surface of the product. Accordingly, there is no need to perform adjustment of the level of the suppressor to accommodate change in thickness of the products. For this reason, not only can the workability of the system be increased, but the attendant worker need not perform a stage replacement.
In a preferred embodiment, the timing at which the suppressor is lowered by the elevator is preferably prior to or immediately after the product having been brought to a position immediately below the suppressor.
As a trigger for the timing at which the suppressor is lowered, a detector is preferably used xe2x80x9cfor detecting an entry of the productxe2x80x9d to a position immediately below the suppressor. To detect the entry of the product this way is intended to mean that the detection may be performed at a position preceding the position at which the product is located below the suppressor, that is, at a position shortly before the entry, or at the time it is brought to the position below the suppressor, or at the moment it is brought to the position immediately below the suppressor.
Also preferably, the force applicator may include at least one pair of eccentric pulleys, each having an axis of rotation extending in a direction parallel to a direction of transport by the transport means, and a belt trained around and between the eccentric pulleys and adapted to travel in a direction perpendicular to the direction of transport, said belt having a portion that protrudes upwardly from a downwardly displaced position below a path of transport defined by the transport means, towards an upwardly displaced position above the path of transport during rotation of the eccentric pulleys to thereby shift the product upwardly. This design advantageously and conveniently makes it possible to simplify the structure of the force applicator.
The present invention in accordance with another aspect thereof provides a product diverting mechanism which includes a force applicator for applying a force, containing a force component acting in a horizontal direction, to the products being transported, in a direction transverse to a direction of transport of the products, and a suppressor disposed above the transport means for suppressing an upward shift of the products which occurs when the force applicator applies the force to the products. The suppressor used therein includes a movable plate supported by a frame for movement up and down between stand-by and lowered positions and also retractable upwardly when the product is brought to a position immediately beneath the suppressor with the movable plate contacting an upper surface of the product, and wherein when the movable plate is lowered with its undersurface contacting an upper surface of the product, the upward shift of the product is suppressed.
According to this aspect of the present invention, when the product is transported to a position beneath the diverting mechanism, the upper surface of the product is brought into contact with the movable plate, causing the movable plate to retract somewhat upwardly while the movable plate applies an urging force to the product. Accordingly, not only can any undesirable upward shift of the product be prevented, but no level adjustment of the suppressor is needed even though the height of the products varies somewhat. Also, although no elevator for elevating the suppressor is employed, additional advantage can be obtained in that the mechanism can be simplified, for example, there is no need to perform an extra electric control to drive the elevator.
If in this structure the weight of the movable plate is utilized to avoid the undesirable upward shift of the product, a meritorious effect can also be obtained in that the urging force acting on the products can be retained at a substantially constant value.